Best approach to switch between TabBarController and ViewController - ios

Question

I have been trying an app with initial login screen which then takes to a TabBarController.
I want to know whats the best approach to do this any example code would be appreciated. I have tried it but I am unable to switch from ViewController to TabController.

Answer 1

I'm not sure that this is the best way to do it, but it's quick and dirty and works. Present a modal view controller inside your applicationDidFinishLaunchineWithOptions: method. You should replace the #selector with something more appropriate to what you want to do. Background color is for effect only.
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
// Override point for customization after application launch.
UIViewController *viewController1 = [[FirstViewController alloc] initWithNibName:#"FirstViewController" bundle:nil];
UIViewController *viewController2 = [[SecondViewController alloc] initWithNibName:#"SecondViewController" bundle:nil];
self.tabBarController = [[UITabBarController alloc] init];
self.tabBarController.viewControllers = #[viewController1, viewController2];
self.window.rootViewController = self.tabBarController;
[self.window makeKeyAndVisible];
// ***** The relevant code *****
UIViewController *viewController = [[UIViewController alloc] init];
UINavigationController *navigationController = [[UINavigationController alloc] initWithRootViewController:viewController];
[[viewController view] setBackgroundColor:[UIColor redColor]];
UIButton *dismissButton = [UIButton buttonWithType:UIButtonTypeRoundedRect];
[dismissButton setFrame:CGRectMake(10, 10, 300, 44)];
[dismissButton setTitle:#"Dismiss" forState:UIControlStateNormal];
[dismissButton addTarget:[self tabBarController] action:#selector(dismissModalViewControllerAnimated:) forControlEvents:UIControlEventTouchUpInside];
[[viewController view] addSubview:dismissButton];
[[self tabBarController] presentViewController:navigationController animated:NO completion:nil];
return YES;
}
I normally wouldn't like to put this sort of code in the app delegate, but if it's a one-time thing like login details, maybe it's ok.

Answer 2

Assume your root view controller is also your login view.
Now from your root view controller, you can present the tab bar controller a number of ways. One way is to just call the presentViewController method from the root view controller.
Setup
From within the root view controller, sometime before presenting the tab bar, set it up:
myTabBarViewController = [[MyTabBarViewController alloc] init];
[myTabBarViewController setModalPresentationStyle:UIModalPresentationFullScreen];
[myTabBarViewController setModalTransitionStyle:UIModalTransitionStyleFlipHorizontal];
[myTabBarViewController setRootTabBarDelegate:self];
Presentation
When you are ready to present, just call this:
[self presentViewController:myTabBarViewController animated:YES completion:nil];
Notes
The view controller hierarchy looks like this:
AppDelegate
L RootViewController
L MyTabBarController